Tape drive unit where reverse rotation of a motor determines travel direction and speed of a tape

ABSTRACT

The tape drive unit of the present invention is constructed such that the reverse rotation of a motor (16) causes a mode cam (32) to drive for setting any mode of normal play, reverse play, fast forward and rewinding. Thereafter the forward rotation of the motor (16) causes a reel shaft (3) or a reel shaft (4) to rotationally drive according to the mode and a head base (51) is slid in normal play or reverse play modes, to set up a magnetic head and pinch rollers. With such construction, each operation of normal play, reverse play, fast forward and rewinding can be performed without using a plunger or microcomputer, thereby eliminating the fear of troubles due to the plunger malfunction or a microcomputer bug.

This is a continuation of application Ser. No. 08/694,609, filed on Aug.9, 1996, now abandoned, which is a continuation of application Ser. No.08/409,881, filed on Mar. 21, 1995, now U.S. Pat. No. 5,621,587, whichis a continuation of Ser. No. 08/066,036 filed on Jun. 2, 1993 nowabandoned.

DESCRIPTION

1. Technical Field

The present invention is related to a tape drive unit which is suitablyused, for instance, in a portable compact cassette player.

2. Background Art

At present, cassette players usually have respective operationalfunctions: normal running (will hereinafter be described as FWD),reverse running (will hereinafter be described as REV), fast running(will hereinafter be described as FF), and rewind (hereinafter describedas REW) of a tape.

In tape drive units which have been employed in such kinds of cassetteplayers, there was proposed the one which is provided with a cam gearhaving a cam face formed on its principal plane side, thereby forselectively switching the operation modes such as FWD, REV, FF, REWmodes and so on.

In such tape drive unit, when the above-mentioned cam gear is rotated, amode switching mechanism for switching said each operation mode isoperated by means of the above-mentioned cam face. The rotational angleposition of the cam gear and said each operation mode are made tocorrespond to each other. That is, by rotating the cam gear by a motoror the like and stopping it at a predetermined rotational angle positionfor positioning, a predetermined operation mode is selected.

For instance, in the tape drive unit having a mode switching mechanismof a reverse-type recording/reproducing device, which is proposed inJapanese laid-open patent publication No. 62-163353 by the applicant ofthis case, the driving force of a single drive motor rotates andoperates a pair of capstans for allowing a tape to travel to the FWD andREV sides, a reel shaft on which a tape reel is mounted for taking upthe tape that was made to travel, and a cam gear for selectivelyswitching a plurality of operation modes, respectively. That is, thedriving force of the drive motor is transmitted to the capstans, reelshaft, etc. through a driving force transmission mechanism comprising apredetermined driving belt, gear and the like.

The cam gear has a gear portion having a plurality of tooth lackingportions formed on the outer periphery thereof, and has a predeterminedcam face and a portion to be engaged which is protrusively provided onthe major surface thereof. The cam gear is positioned through engagementof the portion to be engaged by a cam gear engaging member at arotational angle position, at which the drive gear which transmits thedriving force of the drive motor corresponds to the tooth lackingportions. The cam gear engaging member is constructed to be reciprocatedby a plunger and an activating spring.

When the cam gear rotates, a mode switching mechanism for switching theoperation mode is operated by the cam face. The mode switching mechanismis formed such that a predetermined operation mode can be selected byswitching the transmission path of he driving force through an operationof moving the shaft of a gear for transmitting the driving force of thedrive motor and by switching the travel direction of the tape throughselectively pressing a pinch roller against the pair of capstans or thelike.

That is, in the tape drive unit, to switch the operation mode, theplunger is actuated to release the engagement with the cam gear andengage the drive gear with the gear portion, thereby for rotating thecam gear. Whereupon, the mode switching mechanism is operated and thetape traveling direction and the like are switched. The mode switchingmechanism is operated according to the rotational angle position of thecam gear for switching to a predetermined mode corresponding to therotational angle position. Accordingly, when the operation mode has beenchanged to a desired one, the desired operation mode is selected byreleasing the actuation of the plunger and engaging and positioning thecam gear by the cam gear engaging member.

However, since the plunger has been required in the prior art asdescribed above, there is a disadvantage that the cost will increaseaccordingly, and timing is important for the plunger trigger operation,in which a malfunction tends to occur, and the plunger itself is a partwhich easily malfunctions by the influence of dusts and the like. Inaddition, a microcomputer is needed because of complicated control,which also leads to increase in the cost, and malfunction also tends tooccur due to the bug of the microcomputer. Moreover, there are variousproblems such as the need for care for resetting after batteryreplacement because of the electrical mode control, the difficulty ofunderstanding the operation and the difficulty of service due tomicrocomputer control, and the like.

This invention was accomplished in view of such points, and the objectof which is to provide a tape drive unit that requires no plunger andmicrocomputer thereby solving the above problems.

DISCLOSURE OF THE INVENTION

A first present invention comprises a motor which is forwardly andreversely rotatable, a pair of reel shafts for driving a tape reelhaving a magnetic tape wound thereon, mode setting means driven by thereverse rotation of the motor for forming the respective modes which setthe tape traveling direction and tape traveling speed, and driving meansdriven by the forward rotation of the motor for driving the reel shaftsaccording to the mode formed by the mode setting means, wherein aftersetting a mode by the reverse rotation of the motor, the reel shafts aredriven by the forward rotation of the motor according to the mode thatwas set above.

In a second present invention, the setting means in the tape drive unitof the first present invention comprises a mode cam member driven by thereverse rotation of the motor, a first switch mechanism moved by themode cam member for switching the tape traveling direction, and a secondswitch mechanism moved by the mode cam member for switching the tapetraveling speed.

In a third present invention, the setting means in the second presentinvention comprises detecting means for detecting the positional stateof the mode cam member.

In a fourth present invention, the driving means in the tape drive unitof the first present invention comprises a first transmission mechanismfor transmitting the rotational driving force of the motor to either ofthe pair of reel shafts, and a second transmission mechanism fortransmission to the other reel shaft, wherein the rotational drivingforce of the motor is selectively transmitted to the pair of reel shaftspursuant to the mode set by the mode setting means.

A fifth present invention comprises a motor which is forwardly andreversely rotatable, a pair of reel shafts for driving a magnetic tape,a magnetic head which is provided movably between a first position atwhich it can record on and/or reproduce from the magnetic tape and asecond position at which it does not abut on the magnetic tape, a pairof capstans, a pair of pinch rollers corresponding to the pair ofcapstans, respectively, mode setting means driven by the reverserotation of the motor for forming the respective modes for setting thetape traveling direction and the tape traveling speed, moving meansdriven by the forward rotation of the motor for moving the magnetic headaccording to the mode formed by the mode setting means to the firstposition at which the magnetic head can record on and/or reproduce fromthe magnetic tape, switch means driven by the forward rotation of themotor for selectively moving the pair of pinch rollers to cause them toabut on the capstans according to the mode formed by the mode settingmeans, and driving means driven by the forward rotation of the motor fordriving the reel shafts according to the mode formed by the mode settingmeans, wherein after the mode is set by the reverse rotation of themotor, movement of the magnetic head, switching of the pinch rollers,and driving of the reel shafts are carried out by the forward rotationof the motor according to the set mode.

In a sixth present invention, the setting means in the tape drive unitof the fifth present invention comprises a mode cam meter driven by thereverse rotation of the motor, a first switch mechanism moved by themode cam member for switching the tape traveling direction, and a secondswitch mechanism moved by the mode cam member for switching the tapetraveling speed.

In a seventh present invention, the driving means in the tape drive unitof the fifth present invention comprises a first transmission mechanismfor transmitting the rotational driving force of the motor to either ofthe pair of reel shafts, and a second transmission mechanism fortransmitting the rotational driving force of the motor to the other reelshaft, whereby selectively transmitting the rotational driving force ofthe motor to the pair of reel shafts according to the mode set by themode setting means.

Also, in an eighth present invention, the capstans of the fifth presentinvention are rotationally driven by the motor.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a plan view of the front side (the side on which a cassette ismounted) of an embodiment unit;

FIG. 2 is a plan view of the rear side (the mechanism section side) ofthe embodiment unit;

FIG. 3 is a plan view of the rear side (the mechanism section side) ofthe embodiment unit, with a circuit board being removed;

FIGS. 4A and 4B are explanatory views of the cam grooves of a mode cam;

FIG. 5 is an explanatory view of an electromechanical contact fordetecting a rotational position of the mode cam;

FIG. 6 is an explanatory view of the means for detecting a rotationalposition of the mode cam;

FIG. 7 is a perspective view of a main portion of a mode settingmechanism;

FIG. 8 is a perspective view of a setup cam and a set lever;

FIG. 9 is an explanatory view of the driving of the mode cam;

FIGS. 10A and 10B are explanatory views of the mode setting operation ofFWD/FF and REV/REW of the reel shafts;

FIGS. 11A and 11B are explanatory views of the mode setting operation ofFWD/REV and FF/REW of the reel shafts;

FIGS. 12A and 12B are explanatory views of the set lever operation bythe driving of the mode cam;

FIG. 13 is an explanatory view of the driving state of the reel shaftsupon FWD;

FIG. 14 is an explanatory view of the driving state of the reel shaftsupon REV;

FIG. 15 is an explanatory view of the driving state of the reel shaftsupon REW;

FIG. 16 is an explanatory view of the driving state of the reel shaftsupon FF;

FIG. 17 is an explanatory view of the setup operation of the head base;

FIGS. 18A and 18B are explanatory views of the head base sliding by thedriving of the setup cam;

FIG. 19 is an explanatory view of completion of the head base setup;

FIGS. 20A and 20B are explanatory views of an operation by which thereel shafts are driven after completion of the head base setup;

FIGS. 21A and 21B are explanatory views of the switching operation ofpinch rollers;

FIGS. 22A and 22B are explanatory views of the setup operations of themagnetic head and pinch rollers;

FIG. 23 is an explanatory view of the setup release operation of thehead base;

FIGS. 24A, 24B and 24C are explanatory views of the operation of thesetup cam in the setup cam release operation of the head base;

FIG. 25 is a representation showing another example of the shape of afirst swing arm; and

FIG. 26 is a representation showing an example in which a stopper isprovided for the first and second swing arms.

BEST MODE FOR CARRYING OUT THE INVENTION

Shown in this example is a tape drive unit for use with a portablecompact cassette player including the respective operation functions ofFWD, REV, FF and REW.

First, with reference to FIG. 1 the construction of the front side of atape drive unit according to the present invention will be described.

FIG. 1 shows a mechanical chassis (will hereinafter simply referred toas a chassis), and the front side of the chassis 1 is made as a cassettemount portion on which a tape cassette C is mounted. 2a and 2b arereference pins for positioning tape cassette C. 3 is a take-up reelshaft to be engaged with the take-up reel of the tape cassette C, 4 is asupply reel shaft to be engaged with the supply reel of tape cassette, 5is a first capstan for a FWD operation of the tape, and 6 is a secondcapstan for a REV operation of the tape. Further, 7 is a first pinchroller provided correspondingly to the first capstan 5, 8 is a secondpinch roller provided correspondingly to the second capstan 6, and 9 isa magnetic head for reproducing the signal recorded on the tape. Thesefirst and second pinch rollers 7 and 8 and the magnetic head 9 aremovably supported on a supporting plate 10, which is fixed to the endfringe portion of the chassis 1 correspondingly to the front openingportion of the tape cassette C. That is, on the supporting plate 10 atits left and right, a first pinch roller arm 11 and a second pinchroller arm 12 are symmetrically journaled by pivots 13 and 14,respectively, and the first and second pinch rollers 7 and 8 arepivotally supported by the first and second pinch roller arms 11 and 12,respectively. Further, on the supporting plate 10, a head arm 15 ispivotally supported coaxially with the second pinch roller arm 12, andthe magnetic head 9 is fixed on the head arm 15. By a setup mechanismthat will be described later on, the first and second pinch rollers 7and 8 press against the first and second capstans 5 and 6, respectively,with the tape being pinched therebetween, and the magnetic head 9 is setup so as to be pressed in contact with the tape.

Now, the construction of the rear side of the tape drive unit of thisexample will be described with reference to FIG. 2.

In the figure, 16 is a motor as a drive source, 17 is a pulley, 18 and19 are fly wheels which are rotated in unison with the first and secondcapstans 5 and 6, respectively, 20 is a main pulley, and a belt 21 isstretched over driving pulley 16a attached to the driving shaft of themotor 16, pulley 17, pulley 18a formed on the fly wheel 18, the mainpulley 20, and the pulley 19a formed on the fly wheel 19. The motor 16can rotates in both directions of the forward direction (in the figureof this example, clockwise direction) and the reverse direction(counterclockwise direction). The fly wheels 18 and 19 and the mainpulley 20 are rotated by the driving of the motor 16 through the belt21. By the rotation of the fly wheels 18 and 19, the first and secondcapstans 5 and 6 are rotated in unison with them, and by the rotation ofthe main pulley 20, the driving of the reel shafts 3 and 4 and othervarious operations are performed. Arranged and disposed around the mainpulley 20 are structural parts for setting the operation modes of FWD,REV, FF and REW, and for driving the reel shafts 3 and 4 and othermembers accordingly, and the circuit board 22 is fixed to the chassis 1by means of screws 23 so as to cover most of the structural parts.

FIG. 3 shows a state in which the circuit board 22 has been removed.

Under the main pulley 20, first swing arm 24 and second switch arm 25are journaled for free swing and coaxially with the main pulley 20, andfirst and second slide gears 26 and 27 are pivotally supported on thefirst and second swing arms 24 and 25, respectively. The first andsecond slide gears 26 and 27 are respectively meshed with asmall-diameter gear 20a which is integrally formed on the underside ofthe main pulley 26, and are always rotated with the main pulley 20. Thefirst and second slide gears 26 and 27 have small-diameter gears 26a and27a integrally formed on the underside thereof, respectively, and atorque limiter mechanism (slip mechanism) is contained between the firstslide gear 26 and its small-diameter gear 26a, though not shown.Respectively attached to the first and second slide gears 26 and 27 arefriction bodies 28 and 29 made of an elastic material on both sidesthereof, and they are in contact with the underside of the main pulley20 with slight friction, respectively. For this, when the motor 16 isdriven to rotate the main pulley 20, the friction by the friction bodies28 and 29 allows the first and second slide gears 26 and 27 to be movedin the same direction as the rotational direction of the main pulley 20,respectively, when the first and second swing arms 24 and 25 swing.

When the motor 16 is rotated in the forward direction, the first slidegear 26 is meshed with a change-over gear 30 to transmit its rotation totake-up reel shaft 3 or supply reel shaft 4, while when the motor 16 isrotated in the reverse direction, the second slide gear 27 is meshedwith a transmission gear 31 to transmit is rotation to a mode cam 32.

The switch gear 30, which is moved by a mode setting mechanism that willbe described later on, meshes with a transmission gear 33 upon FWD andFF to transmit its rotation to the take-up reel shaft 3, and meshes witha transmission gear 34 for REV and REW to transmit its rotation to thesupply reel shaft 4 through a transmission gear 35.

On the other hand, the mode cam 32 acts to cause the mode settingmechanism to move the position of the change-over gear 30 for setting toeach mode of FWD, REV, FF and REW.

The mode cam 32 is a so-called double cam. That is, a first cam groove32a is formed in the deep portion of the cam, and a second cam groove32b having a different groove width is formed in the shallow portion soas to partially overlap the first cam groove 32a. The first and secondcam grooves 32a and 32b have the groove shapes as shown in FIGS. 4A and4B, respectively, and the portions used for setting the respective FWD,REV, REW and FF modes are continuously formed.

The mode setting mechanism actuated by the mode cam 32 comprises a firstswitch lever 36 and a second switch lever 37. The first switch lever 36,which is pivotally mounted for swing on the chassis 1 by means of apivot 38, has a lift lever 39 attached to a portion thereof, and theswitch gear 30 is pivotally supported on the lift lever 39. That is, asapparent from FIG. 7, the lift lever 39 having the change-over gear 30pivotally supported on a support stem 40 which is provided upright onthe first switch lever 36 is supported in parallel with the first switchlever 36 for rise or fall, and the lift lever 39 is downwardly pressedand biased by the force of a spring 41 fitted over the support stem 40.The lift lever 39 has at one end thereof a recess 42, which is engagedwith a hook-like guide piece 43 protrusively provided on the firstswitch lever 36, whereby the lift lever 39 is constantly allowed to riseor fall at a fixed position without swinging relative to the firstswitch lever 36. In addition, the lift lever 39 is operated to rise orfall by the second switch lever 37 as will be described later. A part ofthe first switch lever 36 is extended in the direction to the mode cam32 and the engaging pin 44 provided upright on the end of that partengages with the first cam groove 32a of the mode cam 32, wherein thefirst switch lever 36 is rotated about the pivot 38 when the mode cam 32is rotated, and the change-over gear 30 moves between the transmissiongear 33 on the take-up reel shaft 3 side and the transmission gear 34 onthe supply reel shaft 4 side to perform the mode switching operation forFWD/FF and REV/REW.

On the other hand, the second switch lever 37 is pivotally mounted forswing on the chassis 1 by means of a pivot 45, and one end of whichcorresponds to a part of the lift lever 39 on the first switch lever 36.A projecting piece 46 is formed on the distal end of the second switchlever 37 corresponding to the lift lever 39, as apparently seen fromFIG. 7, and the upper surface of the projecting piece 46 is in the shapeof a wedge sloped in the swing direction of the second switch lever 37.A part of the second switch lever 37 is extended in the direction to themode cam 32, and an engaging pin 47 provided upright on the extendedportion is engaged with the second cam groove 32b of the mode cam 32,wherein upon rotation of the mode cam 32, the second switch lever 37 isrotated about the pivot 45 and the end portion of second switch levercomes under the lift lever 39, the ramp surface of the projecting piece46 pushes up the lift lever 39 against the force of the spring 41 tocause the change-over gear 30 to rise, thereby performing the modeswitching operation of FWD/REV and FF/REW.

As described above, the setting operations of the respective modes bythe rotation of the mode cam 32 are distributed to rotation ranges of90°, respectively, and detection of the position (mode) is performed bythe output of an electrical contact. That is, in the rear side of thecircuit board 22, in the portion corresponding to the mode cam 32, asshown in FIG. 5, a central annular contact 48 is formed and fourcontacts 49a, 49b, 49c and 49d corresponding to FWD, REV, REW and FF areformed outside the annular contact 48. The four contacts 49a, 49b, 49cand 49d are angularly spaced from each other by 90° and formed in arange of 45°, respectively, and the individual contacts 49a to 49d andthe annular contact 48 are connected to the operation circuit formed onthe circuit board 22. On the other hand, on the upper side of the modecam 32, a conductive plate 50 is attached so as to rotate in harmony, asshown in FIG. 6. The conductive plate 50 has two terminals 50a and 50b,and one terminal 50a is slidably in contact with the annular contact 48,while other terminal 50b is slidably in contact with any one of the fourcontacts 49a to 49d according to the rotational position of the mode cam32. In the operation circuit, detection of the rotational position(mode) is performed according to which one of the four contacts 49a to49d is in contact with the terminal 50b of the conductive plate 50.

Further on the chassis 1, a setup mechanism is constructed forperforming the setup of the pinch rollers 7 and 8 and magnetic head 9upon FWD and REV.

First, between the fly wheels 18 and 19 on both sides, a head base 51 isdisposed slidably in the direction (of arrow a) corresponding to thesetup direction of the pinch rollers 7 and 8 and the magnetic head 9.The head base 51 is constantly slidably biased to the return direction(of arrow b) by spring 53 stretched between it and a pin 52 providedupright on the chassis 1. An engaging hole 54 is formed through a partof the head base 51, and an engaging projection 55 protrusively providedon the rear side of the head arm 15 enters in the engaging hole 54through a through-hole 56 formed on the chassis 1.

To the head base 51, a selector arm 57 is slidably attached in thelateral direction or in the direction perpendicular to the slidingdirection of the head base 51 (arrows c, d directions, see FIG. 21), andthe left and right end portions of the selector arm 57 are bothperpendicularly bent toward the front side of the chassis 1 to formengaging pieces 57a and 57b, which engaging pieces 57a, 57b arecorresponding to the pinch roller arms 11 and 12 through through-holes58a and 58b formed through the chassis 1, respectively. The selector arm57 is slid in cooperation with swing of the first switch lever 36. Thatis, between the first switch lever 36 and the head base 51, conversionarm 59 is pivotally mounted on the chassis 1 by a pivot 60, and one end59a of which is engaged with an engaging recess 61 formed in the firstswitch lever 36 and the other end 59b of which is engaged with anengaging recess 62 formed in the selector arm 57, whereby the swingmovement of the first switch lever 36 is transformed to the slidemovement of the selector arm 57 through the conversion arm 59.

In addition, a projecting piece 63 is vertically formed in a part of thehead base 51, and the projecting piece 63 is projecting to the upperside of the circuit board 22 through a hole 64 formed through thecircuit board 22. A switch 65 is provided on the upper side of thecircuit board 22 correspondingly to the projecting piece 63, and in asetup condition by sliding of the head base 51, a switch 65 is pressedby the projecting piece 63 to be turned ON.

The head base 51 is subjected to a setup operation by rotation of thesetup cam 66 against the force of spring 53. The setup cam 66 isrotatively driven by mesh of the second slide gear 27 with thetransmission gear 67 upon forward rotation of the motor 16, as will bedescribed later on, and a cam face 66a is formed on the underside of thesetup cam 66, and the edge portion of a window hole 51a formed throughthe head base 51 abuts on the cam face 66a by the biasing force ofspring 53. On the upper side of the setup cam 66, a first projectingstep 68a is formed which is substantially concentric around the centralaxis of the rotation of setup cam 66, as seen from FIG. 8, and anon-concentric second projecting step 68b partially having the sameperipheral surface as the first projecting step 68a is formed on theupper surface of the first projecting-step 68a. In the first projectingstep 68a, an engaging recess 69 with which the engaging pin of a setlever to be described later is engaged upon the setup of the head base51 is cut out and formed, and contiguously with the engaging recess 69,an engaging recess 69a declining in the rotation direction of the setupcam 66 is formed.

Further, a set lever 70 is disposed in the vicinity of the setup cam 66.The set lever 70 is fitted over and supported by a shaft stem 71provided upright on the chassis 1 swingably about the stem and movablyin the axial direction thereof, as seen from FIG. 8. On the underside ofone end side of the set lever 70, an engaging pin 72 is protrusivelyprovided correspondingly to the setup cam 66. The set lever 70 is biasedby the force of a spring 75 stretched between a hook 73 formed at oneend thereof and a pin 74 provided upright on the chassis 1 so that theengaging pin 72 constantly abuts on the peripheral surface of the firstprojecting step 68a of the setup cam 66. On the underside of one endside of the set lever 70, a first engaging projection 76 is protrusivelyprovided which abuts on and engages with the engaging projection 24aformed at the tip end of the first swing arm 24, as will be describedlater on, and a second engaging projection 77 and a third engagingprojection 78 are protrusively provided which abut on and engage withthe engaging projection 25a formed at the tip end of the second swingarm 25. In addition, on the other end side of the set lever 70,projection 79 protruding to the mode cam 32 is formed, and the endportion of the second switch lever 37 is extendedly formed so as tocorrespond to the projection 79, whereby the terminal portion 80 of theextended portion presses projection 79 upon REW and FF to cause the setlever 70 to swing against the force of spring 75.

The tape drive unit of this example having the above construction willbe described in detail below.

As the basic operation of the unit of this example, each operation modeof FWD, REV, FF or REW is set by the reverse rotation of the motor 16,and the tape driving corresponding to each operation mode is performedby the forward rotation of the motor 16.

The operation of each portion will now be described in detail.

a. Driving of reel shafts

In the tape drive unit of this example, the motor 16 is first rotatedreversely if the operation button for any of FWD, REv, FF and REW ispressed. When the motor 16 is rotated in the reverse direction, the mainpulley 20 is rotated counterclockwise in the figure. When the mainpulley 20 is thus rotated counterclockwise, as shown in FIG. 9, thefirst and second slide gears 26 and 27 move in the same direction as therotational direction of the main pulley 20 by the friction for the mainpulley 20, and as a result the small-diameter gear 27a of the secondslide gear 27 meshes with the transmission gear 31 to rotate the modecam 32 clockwise. The rotation of the mode cam 32 actuates the first andsecond switch levers 36 and 37, and the mode switching of FWD/FF andREV/REW is performed by the first switch lever 36, while the modeswitching of FWD/REV and FF/REW is performed by the second switch lever37.

First, the mode switching operation of RWD/REV and FF/REW will bedescribed (FIG. 10).

By the movement of the engaging pin 44 along the first cam groove 32a bythe rotation of the mode cam 32, the first switch lever 36 is made topivot on the pivot 38, and as a result, the switch gear 30 is meshedwith either the transmission gear 33 on the take-up reel shaft 3 side orthe transmission gear 34 on the supply reel shaft 4 side. Engagement ofthe switch gear 30 with the transmission gear 34 on the take-up reelshaft 3 side (FIG. 10A) provides a FWD/FF mode, and engagement of theswitch gear 30 with the transmission gear 34 on the supply reel shaft 4side (FIG. 10B) provides a REV/REW mode.

Now, the mode switching operation of FWD/REV and FF/REW will bedescribed (FIG. 11).

By the movement of the engaging pin 47 along the second cam groove 32bby the rotation of the mode cam 32, the second switch lever 37 is madeto pivot on the pivot 45, whereby the switch gear 30 is moved up ordown. That is, if the second switch lever 37 is made to swing and thewedge-shaped projecting piece 46 on the end portion of the second switchlever 37 enters under the lift lever 39, the projecting piece 46 pushesup the lift lever 39 against the force of the spring 41 thereby to setthe switch gear 30 to the rise position (high position), and if theprojecting process 46 of the second switch lever 37 comes out of underthe lift lever 39, the lift lever 39 is pressed down by the force ofspring 41 thereby to set the switch gear 30 to the fall position (lowposition). A FWD/REV mode is provided when the projecting piece 46 ofthe second switch lever 37 is out of the lift lever 39 and the switchgear 30 is at the fall position (low position) (FIG. 11A), and a FF/REWmode is provided when the lift lever 39 is pushed up by the projectingpiece 46 of the second switch lever 37 and the switch gear 30 is at therise position (high position) (FIG. 11B).

That is, the FWD mode is such state that when the switch gear 30 is atthe fall position (low position) and meshes with the transmission gear33 on the take-up reel shaft 3 side, the REV mode is such state thatwhen the switch gear 30 is at the fall position (low position) andmeshes with the transmission gear 34 on the supply reel shaft 4 side,the REW mode is such state that when the switch gear 30 is at the riseposition (high position) and meshes with the transmission gear 34 on thesupply reel shaft 4 side, and the FF mode is such state that when theswitch gear 30 is at the rise position (high position) and meshes withthe transmission gear 33 on the take-up reel shaft 3 side. That is, inthe unit of this example, the respective modes of FWD, REV, REW and FFare continuously switched by the clockwise rotation of the mode cam 32,and detection of their positions is performed by the electrical contactdescribed above.

When the mode position corresponding to the depressed operation buttonof the respective operation buttons for RWD, REV, FF and REW isdetected, according to its electrical contact signal, the motor 16immediately switches to rotation in the direction opposite to the above,or the forward direction. When the motor 16 is rotated in the forwarddirection, the main pulley 20 is rotated in the clockwise direction asshown in the figure. When the main pulley 20 is rotated clockwise inthis way, the first and second slide gears 26 and 27 move in the samedirection as the rotational direction of the main pulley 20 by thefriction for the main pulley 20, and as a result, the small-diametergear 27a of the second slide gear 27 comes out of the transmission gear31 to stop the rotation of the mode cam 32, while the first slide gear26 meshes with the switch gear 30 to perform the driving of take-up reelshaft 3 or supply reel shaft 4 according to each mode set by the modecam 32.

That is, when switch gear 30 is meshed with the transmission gear 33 onthe take-up reel shaft 3 side at the fall position (low position) (FWDmode), the small-diameter gear 26a of the first slide gear 26 mesheswith the switch gear 30 to drive take-up reel shaft 3 as shown in FIG.13, and when the switch gear 30 is meshed with the transmission gear 34on the supply reel shaft 4 side at the fall position (low position) (REVmode) the small-diameter gear 26a of the first slide gear 26 meshes withthe switch gear 30 to drive supply reel shaft 4 as shown in FIG. 14.Further, when the switch gear 30 is meshed with the transmission gear 34on the supply reel shaft 4 side at the rise position (high position)(REW mode), the large-diameter portion of the first slide gear 26 mesheswith the switch gear 30 to drive the supply reel shaft 4 as shown inFIG. 15, and when the switch gear 30 is meshed with the transmissiongear 33 on the take-up reel shaft 3 side at the rise position (highposition) (FF mode), the large-diameter portion of the first slide gear26 meshes with the switch gear 30 to drive the take-up reel shaft 3 asshown in FIG. 16.

Thus, for FWD/REV and REW/FF, the meshing portion of the first slidegear 26 differs according to the difference in the height position ofthe switch gear 30. That is, the small-diameter gear 26a on theunderside of the first slide gear 26 meshes with the switch gear 30 uponFWD/REv and the large-diameter portion of the first slide gear 26 mesheswith the switch gear 30 upon REW/FF, and consequently the reel shaft 3or 4 is rotationally driven at high speed upon REW/FF as compared withupon FWD/REV.

As described above, in the operation wherein the forward rotation of themotor 16 causes the first slide gear 26 to move to be meshed with theswitch gear 30, the first slide gear 26 acts, in a FWD/REV mode, to bemeshed with the switch gear 30 after completion of the setup of the headbase 51 through the engagement of the engaging projection 24a on the tipend of the first swing arm 24 with the first engaging projection 76 ofthe set lever 70 (this operation will be described in detail later on),whereas the first slide gear 26 is straightly meshed with the switchgear 30 without being affected by contrast to the FWD/REV mode, as shownin FIG. 12A, in the REW/FF mode set lever 70 in the REW/FF mode. Thatis, in the as shown in FIG. 12B, the rotation of the mode cam 32 causesa terminal portion 80 of the second switch lever 37 to press theprojection 79 of the set lever 70, whereby the set lever 70 is made toswing against the force of spring 75. As a result, in the movement ofthe first slide gear 26, the engaging projection 24a of the first swingarm 24 does not engage with the first engaging projection 76 of the setlever 70, and accordingly the first slide gear 26 smoothly moves to theswitch gear 30 side without any trouble and meshes therewith.

b. Setup operation of head base

The setup operation of head base 51 in a FWD/REV mode will be describedbelow.

As previously described, when the motor 16 is rotated in the forwarddirection after the completion of the mode setting and the main pulley20 is rotated clockwise, the second slide gear 27 moves to the samedirection as the rotational direction of the main pulley 20 by thefriction between the main pulley 20, and as a result the small-diametergear 27a of the second slide gear 27 comes out of the transmission gear31 of the mode cam 32 and meshes with the transmission gear 67 of thesetup cam 66. At that time, as apparent from FIG. 17, the engagingprojection 25a on the tip end of the second swing arm 25 is made to abuton and meshes with the second engaging projection 77 of the set lever70, thereby maintaining the meshing state of the small-diameter gear 27aof the second slide gear 27 with the transmission gear 67. Thus, therotation of the main pulley 20 is transmitted to the setup cam 66, andhence the setup cam 66 is rotationally driven counterclockwise, and thehead base 51 is slid by the rotation of the setup cam 66 to perform thesetup of the magnetic head 9 and the pinch roller 7 or 8.

That is, when the setup cam 66 is rotated counterclockwise, the cam face66a of the setup cam 66 continuously presses the edge of the window hole51a of the head base 51, as shown in FIG. 18A, whereby the head base 51is slid to the direction of arrow a against the force of spring 53, asshown in FIG. 18B. In addition, in the REW/FF mode, since the set lever70 is pressed and swung by the terminal portion 80 of the second switchlever 37 as described above, the engaging projection 25a of the secondswing arm 25 does not engage with the second engaging projection 77 ofthe set lever 70, and thus the meshing state of the small-diameter gear27a of the second slide gear 27 with the transmission gear 67 is notmaintained so that the head base 51 does not move.

When the head base 51 is slid against the force of the spring 53 asdescribed above, the edge of its engaging hole 54 presses the engagingprojection 55 of the head arm 15, whereby the head arm 15 is swung topress the magnetic head 9 against the tape and the selector arm 57presses and swings the pinch roller arm 11 or 12, by which the pinchroller 7 or 8 is pressed in contact with the capstan 5 or 6. The setupoperation of the pinch roller will be described in detail later. Thesliding of the head base 51 causes the projecting piece 63 to press theswitch 65 to turn the switch 65 ON. The function of the switch 65 willbe described later.

When the head base 51 is thus completely set up, the engaging pin 72 ofthe set lever 70 is engaged with the engaging recess 69 of the setup cam66 by the force of the spring 75 as shown in FIG. 19, whereby the setupcam 66 is locked to be rotatable at that position, and accordingly thehead base 51 is fixed and maintained in this setup state. Concurrentlytherewith, the set lever 70 is made to swing a little by the engagementof the engaging pin 72 with the engaging recess 69 of the setup cam 66,which causes the second engaging projection 77 of the set lever 70 toshift relative to the engaging projection 25a of the second swing arm 25thereby to release the engagement between the two, and as a result, themeshing between the small-diameter gear 27a of the second slide gear 27and the transmission gear 67 is released to stop the rotation of thesetup cam 66.

The unit of this example is constructed such that the reel shaft 3 or 4is not driven until the setup operation of the head base 51 iscompleted. That is, when the motor 16 is forwardly rotated for switchingto the FWD/REV operation of the reel shaft after the completion of themode setting operation by the reverse rotation of the motor 16, theengaging projection 24a of the first swing arm 24 is made to abut on andengage with the first engaging projection 76 of the set lever 70, asshown in FIG. 20A, if the head base 51 has not yet set up, then thefirst slide gear 26 is prevented from moving toward the switch gear 30.In other words, the first slide gear 26 has not yet been meshed with theswitch gear 30 at this stage, and thus the reel shaft 3 or 4 is notdriven. Then, when the head base 51 is set up as described above and theengaging pin 72 engages with the engaging recess 69 of the setup cam 66to somewhat swing the set lever 70, the first engaging projection 76 ofthe set lever 70 shifts with respect to the engaging projection 24a ofthe first swing arm 24, as shown in FIG. 20B, thereby to release theengaged condition of the two, and as a result, the first slide gear 26moves in the same direction as the rotational direction of the mainpulley 20 by the friction for the main pulley 20 and meshes with theswitch gear 30, whereby the reel shaft 3 or 4 is driven. That is, in theunit of this example, upon RWD/REV, the reel shaft 3 or 4 is drivenafter the head base 51 or magnetic head 9 and the first pinch roller 7or 8 have been completely set up, which prevents a burden from beingimposed on the tape.

c. Switching operation of pinch rollers

Description will now be made on a switching operation for whether thefirst pinch roller 7 or second pinch roller 8 is to be moved in thesetup of the head base 51.

The switching operation is performed in a ganged relation to therotation of the first switch lever 36 by the rotation of the mode cam32. That is, when the mode cam 32 is rotated by the reverse rotation ofthe motor 16 to cause the first switch lever 36 to pivot on the pivot38, the change-over arm 59 is caused by this to pivot on the pivot 60,and the selector arm 57 on the head base 51 is slid by the pivotalmovement of the change-over arm 59. The selector arm 57 in the FWD modemoves to the left in the figure (direction of arrow c), namely, in thedirection in which one engaging piece 57a is engaged with the tip endengaging portion 11a of the first pinch roller arm 11 (FIG. 21A), and inthe REV mode slides to the right (direction of arrow d), namely, in thedirection in which the other engaging piece 57b is engaged with the tipend engaging portion 12a of the second pinch roller arm 12 (FIG. 21B).Then, when the motor 16 is forwardly rotated to the set up head base 51,the selector arm 57 moves in unison with the head base 51, and upon FWD,one engaging portion 57a presses the tip end engaging portion 11a of thefirst pinch roller arm 11 to press the first pinch roller 7 in contactwith the first capstan 5 (FIG. 22A), while, upon REV, the other engagingpiece 57b presses the tip end engaging portion 12a of the second pinchroller arm 12 to press the second pinch roller 8 in contact with thesecond capstan 6 (FIG. 22B).

d. Stop operation

Description will now be made on the stop operation from the state thateach operation of FWD, REV, FF and REW is performed.

To stop from the FF/REW operation, the motor 16 is immediately stoppedby pressing the stop button on the operation console, whereby thedriving of the reel shaft 3 or 4 is stopped leaving each mechanics as itis.

On the other hand, to stop from the FWD/REV operation, the pressing ofthe stop button causes the motor 16 to stop after switching from theforward rotation back to the reverse rotation. That is, upon FWD/REV,the head base 51 is set up as described above, and in this condition,the switch 65 is turned ON by the projecting piece 63 of the head base51, but, if the stop button is pressed with the switch 65 being ON, themotor 16 is set to be reversely rotated.

When the motor 16 is reversely rotated in this way and the main pulley20 is rotated counterclockwise, the first slide gear 26 moves in thesame direction as the rotational direction of the main pulley 20 by thefriction for the main pulley 20 and disengages from the switch gear 30,whereby the driving of the reel shaft 3 or 4 is stopped.

Simultaneously with this, the second slide gear 27 also moves in thesame direction as the rotational direction of the main pulley 20 and itssmall-diameter gear 27a meshes with the transmission gear 67, thereby torotate the setup cam 66 clockwise (FIG. 23). At this time, the engagingprojection 25a of the second swing arm 25 is made to abut on and engagewith the third engaging projection 78, whereby the meshed state betweenthe small-diameter gear 27a of the second slide gear 27 with thetransmission gear 67 is maintained.

When the setup cam 66 is thus rotated clockwise, the engaging pin 72 ofthe set lever 70 engaged with the engaging recess 69 climbs up onto theramp face 69a as shown in FIG. 24A, and soon completely disengages fromthe engaging recess 69 and made to abut on the peripheral surface of thesecond projecting step 68b as shown in FIG. 24B. By this operation, theset lever 70 is swung a little. Since such swing motion of the set lever70 causes its third engaging projection 78 to shift relative to theengaging projection 25a of the second swing arm 25, the engaged statebetween the two is released, whereby the small-diameter gear 27a of thesecond slide gear 27 disengages from the transmission gear 67. As aresult, the setup cam 66 is freed.

When the setup cam 66 becomes free in this way, the head base 51 is slidby the force of the spring 53 to the direction of arrow b, returning tothe initial position, whereby the magnetic head 9 comes apart from thetape and the pinch roller 7 or 8 also disengages from the first capstan5 or 6. With the return sliding of the head base 51, the setup cam 66also returns to the initial position shown in FIG. 24C, whereby the setlever 70 returns to the initial state in which engaging pin 72 abuts onthe peripheral surface of the first projecting step 68a.

In addition, by the return sliding of the head base 51, the pressing ofswitch 65 by the projecting piece 63 is released to turn the switch 65OFF and turn the power source of the motor 16 OFF, whereby all theoperations are stopped.

The operation of the tape drive unit according to the present inventionhas been described so far.

As apparent from the above description, the tape drive unit according tothe present invention has a simple construction in which an operationmode is set by the reverse rotation of the motor 16 and the operationcorresponding to the set mode is performed by the forward rotation ofthe motor 16, without using a plunger or microcomputer as in the priorart.

Although one embodiment of the present invention has been described, thepresent invention is not intended to be limited to the construction ofthe embodiment.

For instance, first swing arm 24 may have a shape as shown in FIG. 25.That is, the shape example of first swing arm 24 indicates that theengaging projection 24a provided on the distal end in the abovedescribed embodiment is eliminated and instead the engaging projection24b is protrusively provided. The engaging projection 24b is adapted tobe made to abut on the second swing arm 25 in the forward rotation, andby employing such shape, the operation by the engaging projection 24a ofthe first swing arm 24 and the engaging projection 76 of the set lever70 in the above described embodiment can be performed by the secondswing arm 25 and the above engaging projection 24b.

That is, to prevent the reel shafts from being driven until the setupoperation of the head base 51 is completed, in the above describedembodiment, the engaging projection 24a of the first swing arm 24 ismade to abut on and engage with the engaging projection 76 of the setlever 70 thereby to inhibit the first swing arm 24 from swinging,whereas, if the first swing arm 24 is shaped as shown in FIG. 25, thefirst swing arm 24 is inhibited from swinging until the completion ofthe setup of head base 51 since the engaging projection 24b abuts on thesecond swing arm 25 when the first swing arm 24 attempts to swing, andafter the completion of the setup of the head base 51, the second swingarm 25 is disengaged from the engaging projection 77 of the set lever 70and swung, whereby the first swing arm 24 is made swingable.

By thus shaping the first swing arm 24 as shown in FIG. 25, the part canbe made small-sized to reduce the overlapping over the other parts,which is advantageous in space factor and also excellent in reliabilityof the operation.

In addition, as shown in FIG. 26, in order that the respective gears ofthe first and second swing arms 24 and 25 successfully mesh with eachother and the arm position is restricted after the object is attained,stoppers may be provided.

That is, in FIG. 26, 81 is a stopper which the first swing arm 24 abutson and engages with in the forward rotation, and 82 is a stopper whichthe first swing arm 24 abuts on and engages with in the reverse rotationand which the second swing arm 25 abuts on in the forward rotation. Inthis case, the second swing arm 25 is engaged by abutting of theprojection 25b protrusively provided on the underside thereof on thestopper 82. When the second swing arm 25 is reversely rotated, the shaft67a of the transmission gear 67 functions as a stopper. Both stoppers 81and 82 are protrusively provided by cutting and rising from the chassis1.

Further, in the other various portions, various changes andmodifications may be made in the scope not departing from the gist ofthe present invention without being limited to the construction shown inthe above embodiment.

As described above, the tape drive unit of the present invention isconstructed such that the respective operation modes of forward play,reverse play, fast forward and rewinding are set by the reverse rotationof the motor while the tape driving operation corresponding to the modethus set is carried out by the forward rotation of the motor, and usesno plunger or microcomputer as in the prior art. Thus, the cost is helddown accordingly as compared with the prior art and the unit can beprovided at low cost, and in addition there is no fear of troubles dueto the malfunction of a plunger or the bug of a microcomputer. Moreover,since the unit of the present invention basically requires no setuptiming, it does not malfunction, and thus a reliable operation isachieved, for instance, however slow the rotation speed of the motor maybe. In addition, in the unit of the present invention, there is nomalfunction since the mode cam mechanically stores the position, andeven if power is turned off, battery replacement requires no reset sincethe mode is stored. Further, since the unit of the present invention issimple in operation, it has various practical effects which were notseen before, such as easy understanding, repair (service).

Explanation of Reference Numerals

3 . . . the take-up reel shaft

4 . . . the supply reel shaft

5 . . . the first capstan

6 . . . the second capstan

7 . . . the first pinch roller

8 . . . the second pinch roller

9 . . . the magnetic head

16 . . . the motor

20 . . . the main pulley

26 . . . the first slide gear

27 . . . the second slide gear

30 . . . the switch gear

32 . . . the mode cam

36 . . . the first switch levee

37 . . . the second switch lever

51 . . . the head base

57 . . . the selector arm

66 . . . the setup cam

70 . . . the set lever

I claim:
 1. A tape drive unit comprising:a pair of capstans; a pair ofreel shafts for driving a magnetic tape; a magnetic head for recordingand/or reproducing a signal to and/or from the magnetic tape; a singlemotor for driving said reel shafts and said capstans, said motor beingforwardly and reversely rotatable; a pair of pinch rollers eachcorresponding to one of said pair of capstans, wherein each of saidpinch rollers alternately press against said corresponding one of saidpair of capstans; mode setting means driven solely by the reverserotation of the motor for setting tape traveling modes; moving meansdriven only by the forward rotation of said motor for moving saidmagnetic head according to the mode set by said mode setting means;switch means driven only by the forward rotation of said motor, saidswitch means selectively connecting with one of said pinch rollers,depending upon the mode set by the mode setting means; and drive meansdriven only by the forward rotation of the motor for driving the reelshafts according to the mode set by said mode setting means.
 2. A tapedrive unit according to claim 1, wherein the mode setting means furthercomprises a mode cam member driven only by the reverse rotation of saidmotor.